/Engine/Source/Runtime/WebBrowser/Public/WebBrowserViewport.h
Called by Slate when the mouse wheel is used inside the viewport
Whether the event was handled along with possible requests for the system to take action.
virtual [FReply](API\Runtime\SlateCore\Input\FReply) OnMouseWheel ( const [FGeometry](API\Runtime\SlateCore\Layout\FGeometry) & MyGeometry, const [FPointerEvent](API\Runtime\SlateCore\Input\FPointerEvent) & MouseEvent )